The question is, what is Arminianism and how does it differ from Calvinism? Without getting into the theology of Jonathan Edwards, which Rowe refers to in his piece, there is no connection presented between the two. The only clue the article gives about Rush's Arminianism is the biblical concept of freewill; something the bible explicitly denies man has; either in soteriology or in anything else because man is born in sin (Psalm 51), and sin is involved in every decision man makes, including the good works he thinks he does, since his motives are always toward darkness (John 3). Even our love is tainted.
On the contrary, it appears Rush was a pseudo calvinist his entire adult life. His belief in the salvation of all people is bizarre, considering Christ's very words that hell is eternal, "The worm never dies" in Mark 9:44.
In A Sense of Deity (Chicago, 1991), 84, 88, John M. Kloos Jr. emphatically claims Rush was a Calvinist. He writes that while Jonathan Edwards "professed natural ability, but moral inability," Rush "posited a natural and collective inability." Kloos Jr. goes on to explain Rush's goal to bring Christian morality to the republic, with the highest form of ethics.
Not to mention, Henry F. May's seminal work The Enlightenment in America, written in 1976, opened the eyes of scholars to just how prevalent Calvinism was in the forming of the United States. So much so that Calvinists thought Thomas Paine was a Christian. Yet, May believed Rush's Calvinism so influential, he wrote Rush "disliked even more than Hume's teaching, the compromising, watered-down Calvinism of most of the Common Sense philosophers...a believer in Original Sin and Divine Grace" and that he only modified his Calvinism "in one respect only" becoming a universalist.
May writes, "Rush could sound as determinist as Edwards." Rush believed the "Being that created our world never takes his hand, nor his eye, for a single moment, from any part of it." (D. J. d'Elia, Pennsylvania Magazine, XXXIII, 1966, 187-203).
May sources Rush's work The Influence of Physical Causes Upon the Moral Faculty, which shows Rush's reliance on second causes for all of man's problems; disease, memory loss, etc.
Moreover, In The Universalist Movement in America 1770-1880, Ann Lee Bressler also claims Rush was an evangelical Calvinist and remained a believer in original sin and divine grace (p. 19). I will admit Rush thought knowledge was progressing and would make man better and less evil and in that sense he was a child of the enlightenment. Rush probably believed in Original Sin, but I'm not convinced he believed in total depravity in the biblical sense of Romans chapter 3. It is also obvious if Rush was a Universalist, which he became from his belief in Calvinism, then he rejected unconditional election. Rush rejected every point of biblical TULIP, in exchange for a pseudo Calvinist TULIP, while even his belief in divine grace and original sin wasn't biblical.
Rush claimed his universalism was from the bible, not from reason or human knowledge, or rather Rush was influenced by heretical writers and twisted the scriptures to fit the human reason he had read. This is why the founding clergy spoke out against heretical authors. It leads to heresy, as well as corrupting of the church. In the end Rowe is incorrect in his conclusion given it wasn't Arminianism that led Rush to universalism; it was his perusal of the five points, especially limited atonement, Irresistible grace and Perseverance of the Saints. In fact, earlier colonial Calvinists had become universalists before him. Rush mistakenly took John 3:16 out of context as well as some other verses, to neglect the larger revelation. Then he twisted grace to apply to everyone and he already adhered to perseverance and combined it all together. Such was the path of Benjamin Rush who wrote in The Road to Fulfillment, The Law of Truth:
And truth indeed is infinite, for there is a truth about everything. But if in our search for truth we fater and fear to go forward because we fear to go astray, here are a few directions to help us. First, we must state clearly to ourselves the problem that puzzles us. If this does not bring the answer, search the Scriptures, especially the New Testament, to see if we can find the answer. But we must be sure that the answer is in accord with the whole body of our Saviour's teaching. If we are still in doubt, pray for guidance by the Holy Spirit, quieting the mind in readiness to receive the answer..The ultimate truth is embodied in Jesus Christ, in His life, His example, and His Teachings.